1. Field of the Invention
The present invention relates to an imaging lens composed of two lens sheets and, in particular, to an imaging lens suitable as a taking lens for a video camera or still video camera used for TV phone, door phone, monitoring purposes, or the like.
2. Description of the Prior Art
Recently, solid-state imaging devices have often been placed on imaging surfaces of various kinds of video cameras and still video cameras. With the advance of technology, such solid-state imaging devices have been reducing their size year by year, accompanying demands for imaging lenses to attain smaller size, wider angle of view, and lower cost.
Conventionally known as the imaging lens used for the above-mentioned purposes is the one disclosed in Japanese Unexamined Patent Publication No. 6-67091 or the like. The back focus of the imaging lens disclosed in this publication, however, is so long that it may not always satisfy the demand for smaller size.
An imaging lens composed of two lens sheets made of glass has already been disclosed in a commonly-assigned application (Japanese Unexamined Patent Publication No. 7-168092). Though this imaging lens, composed of two lens sheets, has a small total length which can satisfy the demand for smaller size, its angle of view decreases as well, whereby it may fail to fully satisfy the demand for wider angle of view.